keel

I've only built two ships to-date and have attached the keel assembly after the 1st planking as per the kit instructions but is it better to do the keel assembly after the 2nd planking?

Kit was purchased from a hobby store in late 2016, but had apparently been made sometime around 1980. The owner was not sure how he came to have the kit in his store--estate sale?... who knows. The plans (not instructions, mind you) are in four languages: English, Italian, German, French and...